Method of using an artery vein shunt applique

ABSTRACT

An artery-vein shunt having graft material applique secured at its ends is permanently implanted by suturing the applique to the host blood vessels. The shunt is particularly intended for use in hemodialysis.

United States Patent 1 Thomas 51 Jan. 30, 1973 [54] METHOD OF USING AN ARTERY-VEIN SHUNT APPLIQUE [75] Inventor: George 1. Thomas, Seattle, Wash.

[73] Assignee: The Battelle Development Corpora- [52] Cl. ..l28/2l4 R, 128/334 C, 128/348 [51] Int. Cl. ..A6lm 5/00, A61m 25/00 [58] Field of Search...l28/2l4 R, 334 R, 334 C, 348;

[5 6] References Cited UNITED STATES PATENTS 3,409,913 11/1968 Kantrowitz et a1 ..128/334 C X 3,176,690 4/1965 HDoubler ..128/348 FOREIGN PATENTS OR APPLICATIONS 123,660 4/1959 U.S.S.R. ..128/334 R OTHER PUBLICATIONS McDonald et a1., Trans. Amer. Soc. Artif. Int. Organs v01. XIV, 1968, pp. 176180.

Tenckhoff et a1., Trans. Amer. Soc. Artif. lnt. Organs Vol. XIV, 1968 pp. 181-186.

Primary ExaminerDalton 1... Truluck Attorney-Stowe" & Stowell [57] ABSTRACT An artery-vein shunt having graft material applique secured at its ends is permanently implanted by suturing the applique t0 the host blood vessels. The shunt is particularly intended for use in hemodialysis.

2 Claims, 4 Drawing Figures PATENTEDJAH 30 I973 INVENTOR GEORGE I. THOMAS ATTORNEYS METHOD OF USING AN ARTERY-VEIN SHUNT APPLIQUE This application is a continuation-in-part of my earlier application Ser. No. 45,331, filed June 1 1, 1970 and now abandoned. The invention described herein was made in the course of work under a contract from the Department of Health, Education and Welfare.

This invention relates to an artery-vein shunt applique. In one specific aspect, it relates to an arteryvein shunt adapted for permanent attachment to a patients circulatory system and intended for use in conjunction with a hemodialysis device.

Periodic hemodialysis iS Ifiquired by a patient whose kidneys havev been removed or are otherwise inadequate. The patients blood is circulated through a Y dialyzer, essentially a semi-permeable membrane separating the blood from a dialysis solution having about the same salt content, osmotic pressure and pH of normal blood plasma, The membrane is impermeable to blood proteins but is permeable to nitrogenous and other bodily waste products which pass from the patients blood to the expendable dialysis solution.

A major problem in periodic hemodialysis is linkage of the dialyzer to the circulatory system of the patient. Unfortunately, the peripheral artery-vein shunts now utilized require frequent surgical revision. Blood vessel stenosis, occlusion, pseudoaneurysm formation, hemorrhage, infection, skin ulceration, and extrusion of the cannular body disrupt the shunt and necessitate arterial and/or venous recannulation. Suitable cannulation sites on a given patient become fewer and more difficult to locate as multiple recannulations are performed on the patient.

I have now discovered an applique whereby an artery-vein shunt can be permanently attached to the host blood vessels virtually avoiding the difficulties noted above and the necessity for frequent recannulation.

It is, therefore, a principal object of the present invention to provide a novel artery-vein shunt applique suitable for permanent attachment to the host blood vessels.

It is a further object of the invention to provide a method for the implantation of an artery-vein shunt which minimizes undesirable side effects attributed to the presence of the shunt and obviates the necessity for frequent recannulation.

These and other objectives and advantages of the present invention will become apparent on consideration of the artery-vein shunt applique more fully described in the following discussion and accompanying drawings, wherein:

FIG. 1 is a perspective view of one form of the artery-v vein shunt applique of the invention;

FIG. 2 is an enlarged perspective view of a single branch of an applique as shown in FIG. 1;

FIG. 3 is a perspective view of a portion of the branch of FIG. 2 attached to a blood vessel; and

FIG. 4 is a schematic view of an artery-vein shunt applique according to the invention positioned on the anterior thigh of a patient with a portion of the shunt broken away to show a connector between the constituent arterial and venous branches.

In its broadest aspect, the present invention is an artery-vein shunt applique comprising artery-vein shunt having graft material secured thereto at each end; the invention also includes the individual branches of the shunt applique.

The present invention further contemplates a method for implanting an arterywein shunt which comprises attaching a first elastomeric tube to a surgically pre-formed opening in an artery by suturing graft material secured at one end of the tube to the edges of the opening in the artery, attaching a second elastomeric tube to a surgically preformed opening in a vein by suturing graft material secured at one end of the tube to the edges of the opening in the vein; and connecting the free ends of the first and second elastomeric tubes.

Referring now to the drawings in more detail, FIG. 1 is illustrative of an artery-vein shunt applique according to the present invention. The shunt applique comprises two branches, essentially elastomeric tubes 21 and 21', particularly adapted for attachment to a blood vessel. The two branches may initially constitute a unitary applique as shown or be provided as separate branches,

As more clearly shown in FIG. 2 each branch has graft material 23 secured at one end. The graft material is made of knit, woven, felt or other open construction. While natural or synthetic material may be utilized, synthetic materials, such as polyethylene terephthalate (Dacron) or polytetrafluoroethylene (Teflon), are preferred for reasons of cost, convenience in handling and sterilization and particularly because of their excellent acceptance by body tissue. The graft material is secured angularly at the end of the branch for convenience in attaching to a blood vessel. The medial portion of the branch bears an infection barrier wrap 22, generally of the same fabric as the graft material. Preferably, the wrap constitutes a contiguous extension of the graft material located at the end of the branch. The elastomeric tube constituting the branch is generally fabricated of silicone rubber (Silastic) acceptable to bodily tissues.

FIG. 3 shows the branch 21 attached by suturing via the graft material 23 to blood vessel at an angle approximating that of a normal branch artery or vein.

FIG. 4 shows an artery-vein shunt, after attachment is completed, positioned on the anterior thigh of a patient. The infection barrier wraps 22 and 22' are located under the skin at the points of exit of the arterial and venous branches, respectively. The two branches of the shunt are joined by means of a double bevelled connector 30, removable for connection to the blood inlet and outlet ports of a hemodialyzer, i.e., artificial kidney. The shunt is rejoined by means of the connector after the dialysis treatment is discontinued.

The shunt is attached to surgically preformed openings, in the host blood vessels. For arterial attachment, a longitudinal incision is made in the host artery and the graft material is sutured to the cut edges of the artery to provide a leak-free junction. For venous attachment, a longitudinal incision is made in the host vein and the other branch similarly sutured to the cut edges of the vein.

The operative technique utilized for implantation of the shunt applique in the femoral region of the anterior thigh is as follows. Under spinal or epidural anesthesia, the side selected for implantation is prepared and draped from the lower quadrant to the knee, with the surgeon capable of externally rotating and froglegging the leg when exposing the femoral vessels. An oblique incision approximately 2.5-3.0 inches long is made immediately distal to the inguinal crease in order to bring the more lateral part of the incision over the common femoral artery and the medial part of the incision over the slightly lower sapheno-femoral junction. Each of the respective vessels is isolated by dissecting through the fibrolymphatic and subcutaneous tissue in a longitudinal direction, preserving the bridge containing multiple femoral lymph nodes. This reduces lymph wound drainage later. The saphenous vein is isolated approximately 1.0-1.5 inches distal to the sapheno-femoral junction and ligated with 1/10 silk. This silk suture is preserved as a traction suture for cannulation of the sapheno-femoral vein at a later step.

The common femoral, superficial femoral and profunda femoral arteries are individually dissected from adjacent tissue and taped with umbilical tape. It is important to get a good length of common femoral artery which may require dissection under the inguinal ligament. A longitudinal arteriotomy somewhat over 1 inch in length is made for the Dacron applique, which is sutured with an over-and-over stitch, utilizing 5/0 Mersilene or polyethylene suture material. Each apex of the applique is fixed with an everting mattress suture. The distal clamp is released temporarily, flooding the segment of vessel occluded for the applique attachment, and this effectively pre-clots the Dacron graft. The venous applique is sutured to a longitudinal venotomy in'a manner identified to that of the arterial branch.

After pre-clotting the arterial applique, arterial circulation is restored through the common and superficial femoral artery system. Further hemostasis, if necessary, is accomplished with interrupted sutures. It frequently takes to minutes to get a sealed and non-bleeding Dacron patch because of occasional clotting deficits in chronic uremics.

The two branches arterial and venous, are separated by cutting if still unitary, trimmed to size and then joined with a double-bevelled Teflon connector before the shunt is opened. The wound is intermittently irrigated with the bacitracin solution, 50,000 units-per 100 cc of saline. The points of skin exit of both branches are then ascertained at points approximately one-fourth inch distal to the infection barrier wrap of Dacron that has been affixed to the Silastic tubes. These exit sites, about 4 inches below the initial incision, are made with the tapered stainless steel, slightly angulated trocar needle passed through a finger-dissected subcutaneous tunnel. The separated Silastic branches are then brought outward again joined with the double bevel Teflon connector. The curve of the exteriorized shunt is placed on the anterior aspect of the thigh, rather than medially or laterally, since this position is approved by virtually all of the patients. The wound is then drained with one or two soft Penrose drains (tubing containing a length of absorbent gauze), removed after several days, and closed in multiple layers. Antibiotics are used liberally in the post-operative period and continued for several weeks.

It is imperative to avoid stitching through the area of the applique cloth that is impregnated with Silastic. A puncture in the Silastic will permit leakage that will not be self-correcting by deposition of fibrin.

Prior to use, the shunts and connectors are packaged in tear-open polyethylene bags and gas sterilized, when sterilized in their original bag, utilizing normal gas sterilization procedures and venting period. The storage period found suitable in the hospital for commercial polyethylene packages should be followed. If autoclave sterilization is necessary due to time limitations, the shunt and connectors must be removed from the polyethylene package and rewrapped appropriately, maintaining proper cleanliness.

Twenty-nine patients (15 males and 14 females) received the shunt for periodic hemodialysis requirements. The patient was permitted to walk within 48 hours after insertion, usually coinciding with discharge from the hospital. The first patient, after? months, required an exchange of her original pediatric size (2.6 mm i.d.) shunt for an adult size (3.1 mm i.d.) to better suit her dialysis requirements. Four patients shunts temporarily clotted, all within the first month of shunt life, without evidence of arterial or venous obstruction. Three of these patients had a history of a tendency to clot cannulae and their artificial kidneys, and are now maintained on anticoagulants at increased levels.

Infection occurredin two patients at the tube exit site. One gram of intravenous vancomycin and oral cloxacillin eradicated the infection over a brief period of time. There has been no-indication of reoccurrence of infection over a seven months follow-up period.

Exit site or wound bleeding significant enough to see the patient as an emergency occurred in four cases. These occurred early in the shunt life and probably represented loss of fibrin integrity in the loosely knit applique graft material. Heparin dosage, while on the kidney, was reduced and bleeding has not reoccurred. After these episodes, arteriograms revealed no graft separation, aneurysm or pseudoaneurysm formation or prominent patch leak.

When located on the anterior groin, the shunt implanted according to the present invention is concealed and easily manageable. Cleanliness of the skin in the area of implantation is important but presents no real problem. Acceptance of the shunt by the patient is excellent.

Artery-vein shunts implanted using the applique of the present invention have been in continuous use for over a year in patients undergoing periodic hemodialysis. Certain of these patientspreviously had been undergoing hemodialysis for times rangingup to 7-% years requiring 3-5 operations per year to maintain patency of conventional cannulae. Such recannulation procedures are both time-consuming and painful. As vessels more proximal to the original point of entry are utilized, the patency time of the shunt decreases necessitating further and more frequent operations.

Use of a shunt implanted according to the method of the present invention permits high blood flow rates for more efficient dialysis. At the same time, continued blood flow in the host blood vessels past and distal to the point of shunting reduces thrombo-embolism occurrence and promotes long-term patency of the shunt. Foreign materials are not present in the lumen of the host vessels thereby eliminating stenosis at the cannula tip. The graft material at the junction of the shunt with the host blood vessels promotes good healing, prevents sinus tract formation and reduces the incidenceof inelastomeric tube to a surgically pre-formed opening in a vein by suturing graft material secured at one end of the tube to the edges of the opening in the vein, and connecting the free ends of the first and second elastomeric tubes.

2. A method according to claim 1 wherein the elastomeric tubes are attached to the artery and vein at angles approximating that of a branch artery and vein, respectively. 

1. A method for implanting an artery-vein shunt which comprises attaching a first elastomeric tube to a surgically pre-formed opening in an artery by suturing graft material secured at one end of the tube to the edges of the opening in the artery, attaching a second elastomeric tube to a surgically pre-formed opening in a vein by suturing graft material secured at one end of the tube to the edges of the opening in the vein, and connecting the free ends of the first and second elastomeric tubes.
 1. A method for implanting an artery-vein shunt which comprises attaching a first elastomeric tube to a surgically pre-formed opening in an artery by suturing graft material secured at one end of the tube to the edges of the opening in the artery, attaching a second elastomeric tube to a surgically pre-formed opening in a vein by suturing graft material secured at one end of the tube to the edges of the opening in the vein, and connecting the free ends of the first and second elastomeric tubes. 